Stay-bolt for boilers.



E. ILDODDS, B, E. D. STAFFORD & C. HYLAND.

STAY BOLT FOR BOILERS.

APPucAHoN FILED MAR-7,1917.

1,291,782. Pdtented Jan. 21,1919.

WITNESSES l VEN T0185 M 'Nrr ETHAN I. Dorms, BENJAMIN E. n. s'rarronn,AND CHARLES I-IYLAND, or rrr'rsnunen,

PENNSYLVANIA, ASSIGNORS TO FLANNERY BOLT COMPANY,

PENNSYLVANIA.

OF PITTSBURGH,

STAY-BOLT FOR BOILERS.

Specification of Letters Patent.

Patented Jan. 21, 1919.

Application filed March 7, 1917. Serial No. 153,132.

To all whom it may concern:

Be it known that we, ETHAN I. Dorms, BENJAMIN E. D. STAFFORD, andCHARLES HYLAND, citizens of the United States, and residents ofPittsburgh, in the county of Allegheny and State of Pennsylvania, haveinvented certain new and useful Improve.

ments in Stay-Bolts for Boilers; and we do hereby declare the followingto be a full, clear, and exact description 0 the invention, such as willenable others skilled in the art to which it appertains to make and usethe same.

This invention relates to an improvement in stay bolts for boilers, andmore particularly to such as are known in the art as flexible stayboltsand provided with tell-tale holes,--one object of the invention being toprovide simple and efiicient means whereby a tubular bolt body may beprovided with a head at its outer end without necessity for upsettingthe metal of the body portion to form a head, which upsetting wouldclose or contract the tell-tale bore for a prohibitive distance inwardlyfrom the head at the outer end of the bolt.

\Vith this and other objects in view the invention consists in certainnovel features of construction and combinations of parts as hereinafterset forth and pointed out in the claims.

The accompanying drawing is a longitudinal sectional view illustratingan embodiment of our invention.

In the construction of flexible staybolts for boilers, it has beenproposed to provide the bolt with a telltale hole into which steam andwater may enter in the event the bolt becomes ruptured and from whichsteam and water may escape -to denote'the defective condition of thebolt. These tell-tale holes have been made to extend from the headed endof the bolt for a limited distance inwardly from the head, but it isdesirable to cause such tell-tale hole to extend from the headed end ofthe bolt continuously to the inner end thereof and to be capable ofdischarging at said inner end of the bolt. Attempts have been made tocon struct the staybolt from a tubular bar, and in some instances thistubular bar has been formed of two members welded together. In upsettingsuch a bar to force the peripheral face,

head thereon, liable to be closed for a prohibitive distance inwardlyfrom the head.

To obviate these objections and still employ a tubular bar having acontinuous bore, in the manufacture of the bolt, we provide the body 1with a partly spherical head 2 in the form of an annulus havinga convexand the headed end of the bolt may be slotted or recessed as at 10 toreceive a suitable tool. The bore of the annular head 2 is formed withan enlarged portion 3 which extends inwardly from the outer end of thehead and forms an annular shoulder 4. The outer end portion of the boltbody is provided with an annular enlargement 5 which may be formed bymachining the end portion of the bolt body and which occupies theenlarged bore 3 in the head and forms a shoulder 6 against which theshoulder 4; in the head abuts.

In assembling the parts of the bolt, the annular head 2 will be firstapplied to the inner end of the bolt body and then moved outwardly oversaid body. The annular head will then the shrunk onto the bolt body withthe use of a suitable tool.

The inner end portion of the bolt may be threaded, as at 7 to screwthrough the inner boiler sheet, and the continuous bore 8 which formsthe tell-tale hole for the bolt, is permanently closed within the headedouter end of the bolt by means of a suitable metal plug 9. Thus it willbe seen that the tell-tale hole extends from a point within the head atthe outer end of the bolt, continuously to the inner end of the bolt.

Having fully described our invention what we claim as new and desire tosecure by Letters-Patent, is

1. A staybolt comprising a body portion having a shoulder near one end,and an an nular head fixed on said body and having the bore or tell-talehole is an internal shoulder intermediate the ends nular enlargementdisposed in the larger portion of the bore of the annular head andhaving a tool slot in one end; and an annnelar head having a convexouter face, rigidly secured to said bolt body at the slotted endthereof.

In testimony whereof, We have signed this 15 specification in thepresence ofitwo SllbSCI'lb? mg Witnesses.

ETHAN I. DODDS. BENJAMIN E. D. STAFFORD. CHARLES HYLAND.

Witnesses EDWIN- S, ,R-YCE, HAROLD SCHUNEMAN.

fiopiea o2 this p atent may be obtained for five cents each,byaddressing the Commissioner of Patents,

. Waehingtomm. 0."

